(1) Before Any Arrest. Except as otherwise provided by statute, a judicial officer may file a statement of charges in the District Court against a defendant who has not been arrested for that offense upon written application containing an affidavit showing probable cause that the defendant committed the offense charged. If not executed by a peace officer, the affidavit shall be made and signed before a judicial officer.

(2) After Arrest. When a defendant has been arrested without a warrant, unless an information is filed in the District Court, the officer who has custody of the defendant shall (A) forthwith cause a statement of charges to be filed against the defendant in the District Court and (B) at the same time or as soon thereafter as is practicable file an affidavit containing facts showing probable cause that the defendant committed the offense charged.